As a communication market develops, the number of users increases, and data services rise, an air interface resource increasingly becomes a bottleneck to the development of a communication service. If a network in one mode can be used to perform air interface offloading on a network in another mode, not only a throughput rate of an air interface is greatly elevated, but also a construction cost of a network can be reduced, and meanwhile, user experience can be effectively improved.
For example, in the prior art, a technology in which a wireless local area network (Wireless Local Area Networks, hereinafter referred to as WLAN) is adopted to perform offloading on a third generation partnership project (3rd Generation Partnership Project, hereinafter referred to as 3GPP) communication system exists, and is used to implement that when the same physical area is covered by both the 3GPP and the WLAN, a part of data streams are transmitted in the 3GPP communication system, and another part of data streams are transmitted in the WLAN, thereby implementing offloading performed by the WLAN on data streams in a 3GPP mobile communication network. In the technology, an offload control server (Offload Control Server) is disposed, and after a user equipment (User Equipment, hereinafter referred to as UE) establishes a radio resource control (Radio Resource Control, hereinafter referred to as RRC) connection in a radio access network (Radio Access Network, hereinafter referred to as RAN), the offload control server instructs the UE to perform WLAN offloading, where this instruction carries an extended service set identifier (Extended Service Set Identifier, hereinafter referred to as ESSID) that corresponds to an access point (Access Point, hereinafter referred to as AP) used in a WLAN. The UE searches a cell in the WLAN according to an ESSID in a received WLAN offloading instruction, so as to obtain a corresponding AP. However, an ESSID in a WLAN AP cannot uniquely identify a cell because a plurality of cells may adopt one ESSID, and different cells may be named with the same one ESSID. Therefore, the UE may access a wrong WLAN AP according to an ESSID, so that the UE needs to perform access again until the UE accesses a correct WLAN AP.
In a process of implementing the present invention, the inventor finds that the prior art has at least the following defects: When the foregoing existing WLAN offload technology is adopted, in a process that a UE accesses a correct WLAN AP, an access delay is too long, and access efficiency is relatively low.